net: ipa: pass the correct size when freeing DMA memory

When the coherent memory is freed in gsi_trans_pool_exit_dma(), we
are mistakenly passing the size of a single element in the pool
rather than the actual allocated size.  Fix this bug.

Fixes: 9dd441e4 ("soc: qcom: ipa: GSI transactions")
Reported-by: Stephen Boyd <swboyd@chromium.org>
Tested-by: Sujit Kautkar <sujitka@chromium.org>
Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20201203215106.17450-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ipa/gsi_trans.c

@@ -156,6 +156,9 @@ int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
 	/* The allocator will give us a power-of-2 number of pages.  But we
 	 * can't guarantee that, so request it.  That way we won't waste any
 	 * memory that would be available beyond the required space.
+	 *
+	 * Note that gsi_trans_pool_exit_dma() assumes the total allocated
+	 * size is exactly (count * size).
 	 */
 	total_size = get_order(total_size) << PAGE_SHIFT;
 
@@ -175,7 +178,9 @@ int gsi_trans_pool_init_dma(struct device *dev, struct gsi_trans_pool *pool,
 
 void gsi_trans_pool_exit_dma(struct device *dev, struct gsi_trans_pool *pool)
 {
-	dma_free_coherent(dev, pool->size, pool->base, pool->addr);
+	size_t total_size = pool->count * pool->size;
+
+	dma_free_coherent(dev, total_size, pool->base, pool->addr);
 	memset(pool, 0, sizeof(*pool));
 }